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[Datsun 1200 encyclopedia]

56-Series Transmission

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Category: Transmission

The 56-series is the stock Datsun 1200 transmission. It was fitted to all RWD B-series Datsuns with A12 and A13 engines. Standard models used 3-speed 56s, while most models used 4-speed versions. The Datsun 1200 GX-5 used a 5-speed version. It was designed to handle the torque of an A12 or A13, but for A14 and A15 engines a 60-Series Transmission is recommended. All of the 3 speed, 4 speed & 5 speed 56 & 56A RWD gearboxes were the same overall length. There were also FWD versions of the 56 gearbox. These are manufactured by Aichi Machine.

Also see: 5-Speeds for an all A-series 5-speeds


Gearbox Numbering

Nissan coding for gearbox models. Example of F4W56L:

  • F: Floor shift (R: remote/column shift)
  • S: overdrive
  • 4: forward speeds (3,4 and 5 were available)
  • W: Warner type sychros (C: competition type synchros)
  • 56: distance in mm between mainshaft and countershaft (with larger distance implying a larger, stronger transmission). Nissan models included 60-Series Transmission and 63-Series Transmission and the 71- used in the bigger Nissans.
  • L: Long extension housing

22959.jpgAlbum click to view

A, B, or C is the evolutionary series for the box as they get older. Some boxes have an L suffix for long extension housing versions. Direct drive boxes have a "direct drive" suffix after the box numbers.

The Nissan chassis code (not transmission code) has F = Five-Speed, and T = 4-speed , e.g. B110GFK was GX Five-Speed. And B110GTK was GX Four-speed. The T holds true for export models as well. The full body codes aren't on the underhood plate, but you'll see some of the extended codes on the cover of the owners manual.

The close ratio 'option' boxes were normally available only as a separate purchase from the Datsun Competition department [through various outlets], so it did not come as a 'factory' option in B110 & B210 models, however I believe that some dealers in Japan were either fitting 'option 1' five speeds, or buying the conversion parts & upgrading the F5W56A gearboxes in new GX5's during pre-delivery for 'special' customers.


56-series is marginal with an A14 (the 56A works OK), but definitely is not strong enough for A14 turbo:
7039.jpgAlbum click to view


Standard trim (STD) Datsun 1200 models came standard with an R3W56 transmission. This was a remote-shift box with a steering-column mounted shifter.

14710.jpg 2760.jpg


The stock sport transmission is fine for city driving. It has wide-spaced gears to allow a steep 1st for easy takeways.

Mainshaft PNs for F4W56 transmissions:
* 32241-H1010 SHAFT-MAIN B110 F4W56L up to 03/73
* 32241-G1101 SHAFT-MAIN B110 F4W56A from 04/73
* 32241-G1101 SHAFT-MAIN B210 F4W56A
* 32241-G1101 SHAFT-MAIN B310 F4W56A
Stock F4W56L3.7572.1691.4041.0003.640
Option #1 (M/C)2.8621.9081.3501.0003.640
Option #2 (U/C)2.1681.5921.2311.000 3.640
Reference: 1984 Nissan Competition Catalog
Number of teeth on gears:
* Counter gear shaft: 29T, 25T, 19T, 13T 
  * 29T (input), 25T (3rd), 19T (2nd), 13T (1st) 
    * +  13T (rev)
* Mainshaft: 19T, 23T, 27T, 31T
  * 19T (input), 23T (3rd), 27T (2nd), 32T (1st), 31T (rev)
  * Reverse idler: 17T
Ratio Computation:
* Input gears: 29/19 = 1.526
* Rev: 29/19 * 17/13 * 31/17 (idler) = 3.640
* 1st: 29/19 * 32/13 = 3.757
* 2nd: 29/19 * 27/19 = 2.169
* 3rd: 29/19 * 23/25 = 1.404
* 4th: 1:1 (direct drive, input shaft linked to output shaft, 
  all output gear pair spin free)

Option 1 Middle-Close Ratio

The option #1 (middle-close) gear set alleviates the 2nd-into-3rd RPM drop that exists with the stock 4-speed. It can only be installed into 1200 transmissions (F4W56L) built up to 3/73.

* 32210-27720 OPT #1 CLUSTER GEAR 16T/20T/26T/29T
* 32230-27720 OPT #1 1ST GEAR 30T
* 32250-27720 OPT #1 2ND GEAR 25T
* 32260-27720 OPT #1 3RD GEAR 23T

Reference: 1984 Nissan Competition Catalog

Option 2 Ultra-Close Ratio

The option #2 (ultra-close) gear set has excellent ratios for racing. The gearset can only be installed into 1200 transmissions (F4W56L) built up to 3/73.

* 32210-H1020 OPT #2 CLUSTER GEAR 19T/23T/26T/29T
* 32230-H1020 OPT #2 1ST GEAR 27T
* 32250-H1020 OPT #1 2ND GEAR 24T
* 32260-H1020 OPT #1 3RD GEAR 21T

Reference: 1984 Nissan Competition Catalog

4-Speed Gear Ratios (GEAR-COUNTER)
ModelNoteGearsetCounter PNteeth
F4W56Lto 0373stock32210-2490029T,25T,19T,13T
F4W56Lto 0373middle-close32210-2772029T,26T,20T,16T
F4W56Lto 0373ultra-close32210-H102029T,26T,23T,19T
F4W56L: All interchange with appropriate matching gears for mainshaft
Gearsearly stocklate stockteethm/cteethu/cteeth
F4W56A: USA B110, starting April 1973. Used through 1982 (listed for A12-powered B210 & B310)

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B10 4-speed

RHD uses a bellcrank release lever, early 56-series
25020.jpgAlbum click to view 25021.jpgAlbum click to view

LHD uses a bellcrank release lever, operated by a hydraulic clutch Slave Cylinder
B10a.jpg B10b.jpg B10c.jpg B10d.jpg B10e.jpg
stamped 'Z U 5 15090'?



Look for "56" in large letters on the right side of the case

  • Missing - 56L (light duty)
  • 56A early (medium duty)
    21400.jpgAlbum click to view
  • 56A late ute (heavy duty)
    1680.jpgAlbum click to view

Also look for the distinctive "ribbing" around the circumference of the front case. Other Nissan transmission are more smooth.

"56" location

This is in various places on the right side of the case. It may be a production variation. All the 56L three speed & four speed gearboxes shared the same gearbox case with integral bellhousing. All the four speed & five speed 56A gearboxes shared the same gearbox case with integral bellhousing. The three speed appears to have been discontinued with the introduction of the 56A series.

Early 56A

The 56A versions are just a model revision, with slight changes. It debuted with the Datsun 1200 Truck (B120) (FEB 1971) with the revised stronger transmission (per the parts catalog). It was then fitted to B210s at introduction (1973) and at the same time export B110s (from April of 1973) were supplied with the 56A.

NOTE: There was an 'L' revision of the 4-speed, but never any 'L' 5-speeds.
* 1966: 56-series intro
* Jan 1970: B110 uses 56L transmission
* Feb 1971: B120 Truck uses 56A revisions
* Apr 1973: B210 production begins in Japan
* Apr 1973: 56A supplied for export B110
* Mar 1975???: Stronger 56A with increase webbing
* new unit plate instead of dust cover
* new plate requires different length release bearing

Note that the 4-speed transmission was redesigned for the 56A revision. Gearsets are not interchangable between early and late transmissions.

Modifications have been made on the following points to strengthen the gears and bearings, and to improve lubrication performance as well as noise and vibration proof at high-speed driving.

  1. Strengthened gears and bearings: Although there is no change in the gear ratio, each gear has an increased width by 0.039 to 0.079 (1 to 2 mm) and the countershaft, front bearing and main shaft bearing are strengthened.
  2. Improved lubrication performance: To ensure proper lubrication in the rear extension bushing, an oil dam is installed in the center of the extension.

Reference: Service Bulletin Vol. 188 "Introduction of New Model Datsun B210 Series" page 69, July 1973, Nissan Motor Co., Ltd. Tokyo Japan Telex: NISMO.

22967.jpgAlbum click to view

Late Model 56A

  • Strong Ribbing
  • 56A and Nissan symbols in separate boxes

Stronger webs on the ribbing
19055.jpgAlbum click to view 19056.jpgAlbum click to view


1990-1994 Sunny Truck has a unique case Extension housing.

w/dual mount flanges
23176.jpgAlbum click to view 23177.jpgAlbum click to view 23178.jpgAlbum click to view


See: 5-speeds for an overview of 5-speeds in general

For the stock B110 5-speed (GX5 gearbox), see,: 5C56

Tail Housing

Late (heavy duty) tail housing has a bumpy knob on top where it meets the case.
21403.jpgAlbum click to view

One or two motor mounts bosses?
21402.jpgAlbum click to view
Early or late can come both ways. Why?

All 8910-up have both. The last one is for an exhaust pipe bracket. Some earliers one have both, however.

One switch or two?
21404.jpgAlbum click to view 8910- has both.

Clutch Lever Type

  • Remote (side) linkage: 3-speed
  • Bell crank linkage: Datsun B10 (Datsun 1000)
    15856.jpgAlbum click to view
  • Hydraulic linkage: LHD models, hole on left side
  • Cable linkage: RHD models, cable hole on right side
    19050.jpgAlbum click to view

Clutch Cable Hole

RHD 4-speeed and 5-speed models use a clutch cable. In the B110, this was a small hole in bellhousing, while it is a larger hole in B210 and B310 models/

21401.jpgAlbum click to view

5-speed: B110 small hole, B210 large hole
19047.jpgAlbum click to view

1976-1994 'Angular-D' shape
26658.jpgAlbum click to view

Gearbox Mount Position

  • Early boxes have a single gearbox mount location
  • Late boxes have two locations

Drain Plug vs. Reverse Switch

  • 4-speed (RHD early models 67-73): reverse switch points straight back
  • 4-speed (later model 1975-up): drain plug points straight back
  • 5-speed: drain plug points down, from middle of adapter plate

Extension Housing Shape

On the Five Speed, the extension housing is a gravity casting (sand casting) which is fatter than the four speed extension, as both reverse and first gear are located in there.
14706.jpgAlbum click to view

The bolts holding the extension to the front case are:

  • Short in 4-speed
  • Long in 5-speed

4777.jpgAlbum click to view

Both first & reverse are in the extention housing which looks to be a gravity casting, while the main case is a pressure die casting.

  • Sandwich plate differs - in the 5-speed, the oil drain plug screws up into this from the bottom.
  • Tail Housing (extension) - 5-speed extension bulkier to encase 1st gear (as well as reverse).
  • Like the four speed, the reverse light switch is also rearward facing in the five speed 56A gearbox.

Electrical Switches

All 56-series transmissions have a reverse switch.

Pink arrow REV switch: left 4-speed, right 5-speed
19048.jpgAlbum click to view

Some newer 4-speeds include one or more of the following, for the purpose of controlling emission gear on the engine:

* Top Switch (high gear detect switch)
* Neutral Switch
4-speed Neutral Switch is near top | Reverse Switch is on bottom
19052.jpgAlbum click to view


5-speed Ratios

The 5-speed transmission (F5C56A) was originally installed on certain non-USA models of the 1200. With the stock gearing this transmission works very well for street, slaloms, high-speed time trials or rallies. With the optional gearing (32010-H7220N), it is the best production-based transmission available for racing versions of the 1200, B210 or 210 Datsuns. The synchro mechanism is the servo-type (steel).

  • 32010-H7251 stock GX-5 5-SPD TRANSMISSION
  • 32010-H7251P OPT #1 W/R 5-SPD TRANSMISSION
  • 32010-H7220N OPT #2 C/R 5-SPD TRANSMISSION
Part No.1st2nd3rd4th5thRev
32010-H7251P W/R3.7572.3741.6591.2911.0004.040
32010-H7220N C/R2.6761.6911.3981.1811.0002.877

Reference: 1984 Nissan Competition Catalog

16819.jpgAlbum click to view Competition198443.jpg

The Counter gear is a single machined piece that includes several gears on one shaft.

5-speed Gear Ratios (GEAR-COUNTER)
ModelNoteGearsetCounter PNteeth
F5C56Awide-ratiostock GX-532213-H720029T,26T,23T,18T,13T
Counter gears interchange if the matching gears are used:
1st32230-H720032T<- same
2nd32250-H720028T<- same

Stock (W/R) gearset
26281.jpgAlbum click to view

C/R gearset
26282.jpgAlbum click to view

Close/Ratio Gearset (uses existing Gear 1 and Gear 2)
26280.jpgAlbum click to view

Straight-cut gear version of C/R gearset (uses stock helical cut Gear 1)
26277.jpgAlbum click to view

4-speed Ratios

Part No.1st2nd3rd4thRev.
Stock 4-speed3.7572.1691.4041.0003.640
OPT 1 M/C2.8621.9081.3501.0003.640
OPT 2 U/C2.1681.5931.2331.0003.640
Datsun 1200 4-speed. Same as B20 Datsun 1000 Pick-up
1st 3.76
2nd 2.17
3rd 1.40
4th 1.00
REV 3.46
4-speed Ratios (GEAR-COUNTER) for F4W56L only (will not fit F4W56A)
ModelNoteGearsetCounter PNteeth
F4W56LOPT 1M/C32210-2772016T,20T,26T,29T
F4W56LOPT 2U/C32210-H102019T,23T,26T,29T
Counter gears interchange if the matching gears are used:
GearStockOPT 1OPT 2
All sets use the same 19T main gear (input shaft)

Stock 4-speed gearset Explanation
13278.jpgAlbum click to view

Middle-Close 4-speed gearset
26279.jpgAlbum click to view

Ultra-Close 4-speed gearset
26278.jpgAlbum click to view

Topgear straight-cut gearset
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Topgear 56A gearset
1st 2.50
2nd 1.64
3rd 1.25
4th 1.00


Sunny truck Long Body vs Short Body uses different transmission. Front case differs slightly, while gears, shifter, and rear extension do not differ.

* 32010-G1650 -8910
* 32010-95W00 8910- [has neutral switch]
* Uses a full engine plate 30411-H5001
* 32010-G1651 -8910
* 32010-95W03 8910- [has neutral switch]
* Uses dust cover 30422-H5010

Smooth Case

Rare smooth-case 56A with no ribs. The casting itself is different. What did it come out of?

19710.jpgAlbum click to view 19711.jpgAlbum click to view 19712.jpgAlbum click to view 19713.jpgAlbum click to view

Another one:

And a smooth-case 5-speed
26069.jpgAlbum click to view 26068.jpgAlbum click to view 26067.jpgAlbum click to view



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